>enemy drops ammo
>gun has 2/9 ammo in the mag and 30/150 in reserve
>pick up ammo
>gun has 2/9 and 150/150
>gun has 2/9 ammo in the mag and 30/150 in reserve
>pick up ammo
>gun has 2/9 and 150/150
>kill rat
>It drops a chainsaw
>It drops a chainsaw